If it was always this way, explain why the IPCC's seminal report on climate change uses the phrases "CO2 enrichment" (rising CO2 levels) and "air pollution" as if they're two different categories?

> 2.2.4 Consequences of CO2 enrichment and climate change for natural terrestrial ecosystems could be modified by other environmental factors, both natural and man induced (e.g. by air pollution).

Help me parse this according to your understanding that "CO2 was an air pollutant 30 years ago." If CO2 is a subcategory of "air pollution," then it makes no sense to list "air pollution" as an example of "other environmental factors." It wouldn't be grammatical. The report uses this basic sentence structure, referring to "CO2 enrichment" as one thing in distinction to "other environmental factors" including "air pollution" several times. Explain to me how that's consistent with your position?